Fix Massive Memory Leak

Pathfinder objects are storing references to ChunkCache's, and never cleaning up.

These ChunkCache's then leak other entity objects. Those entity objects then have leaks to their
own chunk cache. A recursive problem....

Clean up the ChunkCache reference after it is done being used.

Spigot-Server-Patches/0124-Fix-Massive-Memory-Leak.patch

@@ -0,0 +1,28 @@
+From a4e295c985a50926d5e66a184fc764f4aa301d6a Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Thu, 31 Mar 2016 19:06:47 -0400
+Subject: [PATCH] Fix Massive Memory Leak
+
+Pathfinder objects are storing references to ChunkCache's, and never cleaning up.
+
+These ChunkCache's then leak other entity objects. Those entity objects then have leaks to their
+own chunk cache. A recursive problem....
+
+Clean up the ChunkCache reference after it is done being used.
+
+diff --git a/src/main/java/net/minecraft/server/PathfinderAbstract.java b/src/main/java/net/minecraft/server/PathfinderAbstract.java
+index d579577..40e5b4d 100644
+--- a/src/main/java/net/minecraft/server/PathfinderAbstract.java
++++ b/src/main/java/net/minecraft/server/PathfinderAbstract.java
+@@ -23,7 +23,7 @@ public abstract class PathfinderAbstract {
+         this.f = MathHelper.d(entityinsentient.width + 1.0F);
+     }
+ 
+-    public void a() {}
++    public void a() {this.a = (IBlockAccess) null;} // Paper - Fix massive memory leak. Intentionally casting to ensure compile error if obfuscation changes
+ 
+     protected PathPoint a(int i, int j, int k) {
+         int l = PathPoint.b(i, j, k);
+-- 
+2.8.0
+

importmcdev.sh

@@ -54,6 +54,7 @@ import PacketPlayInResourcePackStatus
 import PacketPlayOutPlayerListHeaderFooter
 import PacketPlayOutTitle
 import PacketPlayOutUpdateTime
+import PathfinderAbstract
 import PathfinderGoalFloat
 import PersistentVillage
 import TileEntityEnderChest